1. Field of the Invention
The present invention relates to a method of detecting a PTY burst signal in an RDS receiver, which can automatically receive an arbitrary information program from another network from the beginning of its broadcasting.
2. Description of Background Information
An RDS (Radio Data System) is an FM multiplexed broadcasting system recommended by the CCIR (International Radio Consultative Committee). The RDS provides mainly car radios with various services, such as displaying the name of the broadcasting station, automatic tuning and automatic reception of a traffic information program.
Conventionally, the automatic reception function of an RDS receiver could not receive other than the traffic information of a receiving station previously set in the receiver and its associated station, i.e., the traffic information of stations in a local network. When no traffic information program is broadcasted in this network, therefore, the user cannot get any traffic information all the time.
To solve such a problem, the present applicant has filed a patent application about a traffic information receiving method which can automatically receive traffic information programs of other network stations by an interruption reception (see Japanese Patent Application No. Hei 4-213910). This traffic information receiving method utilizes newly established EON (Enhanced Other Networks) information consisting of 14A and 14B groups to detect that the broadcasting of a traffic information program from another network station has started, and automatically switch the receiving station of the RDS receiver from a previously set this network station to a station in another network to receive traffic information which is currently broadcasted from another network station, by an interruption reception.
This prior art system merely receives traffic information broadcasted from another network station, but cannot receive any other information programs than the traffic information. In receiving an arbitrary information program, it is desirable to start receiving such information program from the beginning. The conventional RDS receivers including the aforementioned prior art system of the present applicant could not accomplish such time-synchronous reception.